Protein Synthesis Flashcards
i hate this
What is the central dogma of biology?
The process where genetic instructions in DNA are used to synthesize proteins, determining traits
What is the relationship between proteins and traits?
Traits are determined by the presence of specific proteins synthesized from genetic instructions
Define a gene
A sequence of nucleotide bases carrying instructions for synthesizing a polypeptide (protein)
What are polypeptides made of?
Monomers called amino acids; there are 20 different amino acids
What are the two main processes of protein synthesis?
- Transcription: mRNA synthesis from DNA
- Translation: Polypeptide synthesis using mRNA instructions
What happens during gene activation in transcription?
The gene is “turned on” to initiate transcription
What is the function of RNA polymerase in transcription?
Binds to the promoter site, unzips DNA strands, and synthesizes mRNA using the antisense strand as a template
What are the sense and antisense strands of DNA?
Sense strand (5’ → 3’): Carries the coding sequence for the protein
Antisense strand (3’ → 5’): Template for mRNA synthesis
How is mRNA modified after transcription?
mRNA is processed and exits the nucleus to reach ribosomes in the cytoplasm
What is the role of mRNA?
Carries instructions for synthesizing polypeptides, read in triplets called codons
Define translation in protein synthesis
The synthesis of a polypeptide on ribosomes using mRNA instructions
What is the role of tRNA in translation?
tRNA carries specific amino acids and complementary anticodons for mRNA codons
What happens at the ribosome during translation?
Ribosomes decode mRNA codons, and tRNA brings amino acids to form a polypeptide chain
How is a polypeptide released during translation?
Translation stops when a stop codon is reached, and the polypeptide is released to form a functional protein
What is the redundancy in the genetic code?
Multiple codons can code for the same amino acid, even though there are 64 codons for 20 amino acids
